The present invention generally relates to semiconductor devices and more particularly to a semiconductor module that includes therein a plurality of semiconductor devices each in turn including a substrate carrying thereon a semiconductor chip. Further, the present invention relates to a semiconductor module assembly including a socket that holds the substrate of the semiconductor device detachably.
Memory semiconductor devices such as DRAMs are used extensively in various information processing apparatuses including personal computers and workstations. In relation to the advancement of such information processing apparatuses, in particular in relation to the advancement of software technology used therein, the storage capacity of the memory semiconductor devices needed in an information processing apparatus is increasing continuously.
In view of the continuous demand of increased memory storage capacity, information processing apparatuses are generally constructed such that the user of the information processing apparatus can upgrade the storage capacity of the memory semiconductor devices as necessary, without discarding the old information processing apparatus.
In the case of personal computers, the upgrading or increase of the memory storage capacity is achieved by adding or replacing a DRAM module called SIMM (single-in-line memory module). In a SIMM module, a plurality of DRAM chips are mounted on a common module substrate that carries a plurality of terminals or contacts on an edge of the module substrate for achieving external interconnection. The SIMM module is thereby mounded on a corresponding socket of a personal computer detachably by engaging the contacts with corresponding contacts of the socket.
Currently the SIMMS having a storage capacity of 16 Mbytes or 32 Mbytes are readily available in the market.
On the other hand, recent progress in the fabrication technology of semiconductor devices has brought a rapid increase in the storage capacity of DRAMs. Thus, it is now possible that a single DRAM chip can have a storage capacity of 32 Mbytes, which has been achieved by a SIMM module that includes a plurality of semiconductor chips. In other words, such a single large capacity DRAM chip can function as a conventional SIMM module.
Generally, a conventional semiconductor chip has been mounted on a mount substrate such as a computer mother board by a soldering process, in which the semiconductor chip and the mount substrate are connected with each other both mechanically and electrically. In the case of CPU chips, on the other hand, it has been practiced to provide a socket on the mount substrate and the CPU chip has been mounted on such a socket in a detachable manner, such that the user of the computer can upgrade the CPU as necessary. As a personal computer uses only one or two CPU chips, such a construction to use a socket for mounting the CPU does not cause a problem in designing the personal computer.
In the case of memory semiconductor devices such as DRAMs that are used in large number in a computer, the mounting structure that uses a socket inevitably increases the size of the mount substrate and hence the size of the computer. Thus, the use of a socket such as the one used for a CPU is not appropriate for the memory semiconductor devices. Because of this reason, the memory semiconductor devices have either been soldered on the mounting substrate of the computer or mounted detachably in the form of a SIMM module.
As noted already, a SIMM module includes a plurality of memory semiconductor devices in the form that semiconductor chips forming the memory semiconductor devices are soldered upon a common module substrate. Thus, a plurality of memory semiconductor chips are mounted simultaneously when a SIMM module is mounted on the mounting substrate of a computer.
When the storage capacity of a memory semiconductor chip has increased as in the case of recent, large capacity memory semiconductor chips, a single memory semiconductor chip can have a storage capacity comparable to that of a conventional SIMM module and can be used in place of such a conventional SIMM module as noted previously. In order to use such a memory semiconductor chip for a conventional SIMM module, it is necessary to provide a mounting structure that enables a detachable mounting of the semiconductor chip on a mounting substrate of a computer. In regard to this demand, it should be noted that conventional memory semiconductor chips have been soldered upon a mount substrate or a module substrate and detachable mounting has not been possible.
Further, in view of expected demand for further storage capacity in future, it is desired that the memory semiconductor chip form a memory module together with similar memory semiconductor chips.
Accordingly, it is a general object of the present invention to provide a novel and useful semiconductor device and a semiconductor module wherein the foregoing problems are eliminated.
Another and more specific object of the present invention is to provide a semiconductor device that includes a single semiconductor chip on a substrate and constructed so as to be mounted on a socket detachably.
Another object of the present invention is to provide a semiconductor module including one or more semiconductor devices, each including a single semiconductor chip on a substrate, and a socket holding said one or more semiconductor devices in a detachable manner.
Another object of the present invention is to provide a semiconductor device, comprising:
a substrate carrying a single semiconductor chip thereon;
an interconnection pattern provided on said substrate in electrical connection with said semiconductor chip; and
a plurality of contacts provided on an edge of said substrate in electrical connection with said interconnection pattern.
Another object of the present invention is to provide a semiconductor module, comprising:
a plurality of semiconductor devices each including: a substrate carrying a single semiconductor chip thereon; an interconnection pattern provided on said substrate; and a plurality of contacts provided on an edge of said substrate in electrical connection with said interconnection pattern; and
a socket holding said plurality of semiconductor devices detachably, said socket engaging said plurality of contacts of said plurality of semiconductor devices detachably.
Another object of the present invention is to provide a socket for holding a plurality of semiconductor devices detachably in an erected state, each of said semiconductor devices carrying a plurality of contacts terminals, said socket including a plurality of socket components provided in correspondence to said plurality of contact terminals on said semiconductor devices, each of said socket components comprising:
a socket main body;
a plurality of contacts provided on said socket main body, said plurality of contacts being adapted for engagement with a plurality of corresponding contact terminals on said plurality of semiconductor devices mechanically, said plurality of contacts on said socket main body establishing an electrical contact with said plurality of corresponding contact terminals of said semiconductor devices and holding said plurality of corresponding contacts of said semiconductor devices detachably; and
a plurality of terminals provided on said socket main body in electrical connection with said plurality of contacts on said socket main body.
Another object of the present invention is to provide a semiconductor module, comprising:
a plurality of semiconductor devices each comprising: a substrate carrying a single semiconductor chip thereon; an interconnection pattern provided on said substrate in electrical connection with said semiconductor chip; and a plurality of contacts provided on an edge of said substrate in electrical connection with said interconnection pattern; and
a socket for holding said plurality of semiconductor devices detachably, said socket comprising: a socket main body; a plurality of contacts provided on socket main body, said plurality of contacts being adapted for engagement with said plurality of contacts provided on each of said plurality of semiconductor devices mechanically, said plurality of contacts on said socket main body establishing an electrical contact with said corresponding contacts of said plurality of semiconductor devices and holding said contacts of said plurality of semiconductor devices detachably; and a plurality of terminals provided on said socket main body in electrical connection with said contacts on said socket main body.
According to the present invention, it becomes possible to form a semiconductor device including a single semiconductor chip, which may be a memory semiconductor chip, on a substrate such that the semiconductor device is detachable from a socket. By using a semiconductor module that includes such a socket on which one or more of the semiconductor devices are detachably mounted in an information processing apparatus such as a personal computer, the user of the computer can increase or decrease the memory size as necessary by adding or removing the semiconductor devices. The construction of the present invention is particularly effective when a memory semiconductor chip of a very large memory size is used in the semiconductor device.
Other objects and further features of the present invention will become apparent from the following detailed description when read in conjunction with the attached drawings.